Organizational environment
The Office of Highway Policy Information (HPPI) has developed the VTRIS WTable
web site. It is available to all the public. The HPPI analytical team
representative, David L. Jones, can be reached at (202) 3665053.
System Availability
VTRIS W Reports are available:
Monday Friday: 7 a.m. To 10 p.m. (EST)
Sunday: 12 Noon To 10 p.m. (EST)
Reports Subsystem
The VTRIS WTables are designed to provide a standard format for presenting the
outcome of the Vehicle Weighing and Classification efforts at truck weigh
sites. The data that appears in the WTables comes from the Summary files that
are generated by the Summary subsystem.
VTRIS W2 Table
This table displays a Summary of the Vehicle Counted and the Vehicle Weighed for
selected stations by Vehicle Classification. The Vehicle Classification data is
averaged for each hour and the 24 hourly averages are added for the average
daily count. The W2 Table breaks the data down by the 13 Vehicle type
categories. But this table considers weight information for Vehicle type 5
through 13.
VTRIS W3 Table
This table contains information on the Average Weights of Empty, Loaded and all
Trucks and their Estimated Average Carried Load. This information is broken
down by Vehicle Classification 5 through 13 for each Station location. This
process uses weight measurements and the set of breakpoints between empty and
loaded trucks to calculate Percent Load, Percent Empty, Average Load Weight and
Average Empty Weight.
VTRIS W4 Table
This process is most commonly used in Pavement design since it contains
information on Truck Axle loadings and their effect on Flexible and Rigid
Pavement based on 18KIP Equivalent Axle Load. This process builds three
different sections:
I) Equivalency Factors provides the Number of Single, Tandem, Tridem and
Quad axles weighed which fall into particular weight ranges and gives the
resulting 18KIP Equivalent Axle Loads on the two type of Pavement
II) Equivalency Summary contains information on the Summary ESAL
(Equivalent Single Axle Load) Design Factors such as ESAL per Vehicle, Percent
Distribution for Flexible and Rigid Pavements and Truck percent.
III) 20 Year ESAL Estimates displays Flexible and Rigid pavements
Growth Rates for percent Truck. For all sections, information is grouped by
Truck type 3 through 13 and can be shown for selected station(s), location(s)
and/or highway Functional Classification(s).
User defines the Ranges of Axle Load in 18KIP for four types of axles. The
default for parameters are:
Single Axle
Starting: 1.0
Interval: 1.0
Ending : 20.0
Tandem Axle
Starting: 2.0
Interval: 2.0
Ending : 40.0
Tridem Axle
Starting: 3.0
Interval: 3.0
Ending : 60.0
Quad Axle
Starting: 4.0
Interval: 4.0
Ending : 80.0
Those ranges are to be used in calculation of the Equivalent Single Axle Load
(ESAL) coefficients for Flexible and Rigid surfaces. The following expressions
determine special coefficients depending on Axle Load in KIPs (X) and type of
Axles (Y) where Y can be 1 (Single), 2 (Tandem), 3 (Tridem) or 4 (Quad)
VTRIS W5 Table
This table shows the Number of Trucks Weighed in various Gross Weight ranges,
Total Average Vehicles Weighed and Total Average Vehicles Counted. This process
produces values for Truck types 3 through 13 and shows for selected station(s)
and/or Functional Classification(s) of highway. User defines the Ranges of
Gross Weight. The default for parameters are :
Starting Value: 5
Interval: 2
VTRIS W6 Table
This table gives the Number and Percent of Vehicle by type exceeding a User
specified Axle, Tandem and Gross Weight Limit (i.e. all Violations of the
Bridge Formula). A vehicle may have multiple violations of the set criteria.
The information can be shown by station(s) and /or Functional Classification(s)
of highway and is broken down by Vehicle type 3 trough 13. The User assigns the
Limit Value Axle Weight range for Single, Tandem, Tridem and Quad Axles and
Gross Weight. The default for parameters are:
Single : 9070
Tandem: 15420
Tridem: 0
Quad: 0
Gross: 36290
The Number Exceed and the Percent Exceed are calculated for each Axle Type and
Gross Weight. For the Number Exceed to sum up the number of axles of each type
(Single, Tandem, Tridem, Quad and Gross) from the limit value to the maximum
number of weight interval. This table includes the Violations of the Bridge
Gross Weight Formula depending only on Vehicle type. The Bridge Gross Weight
Formula provides a standard to control the spacing of Truck axles on the
Vehicle that uses highway bridge. The Number of Violations of the Bridge Gross
Weight Formula calculated previously are in the Summary process.
VTRIS W7 Table
This table gives the Number and Percent of Average Daily Count for those
measurements where Axle Load above a Limit. The Gross Weight Limits by Vehicle
Class (in Kilograms) was assigned by the User. The default is equal to:
VT_Limit[j] = {18140, 24490, 33570, 33570, 36290, 36290, 36290, 36290, 36290 }
where j = 5, 13 for each vehicle type respectively.
The information can be shown for each station(s) and/or Functional
Classification(s) of highway broken down by Vehicle types 5 through 13.
The Numbers and Percentage shown under the "In Excess" column are the vehicles
that are classified as overweight in their respective Axle groupings. Numbers
under the "Not in Excess" column plus the "In Excess" column should add to the
"Number Weighted/Avg. Daily Count". For further information about the VTRIS
WTable Reports and the VTRIS (Vehicle Travel Information System) software. Go
to http://www.fhwa.dot.gov/ohim/ohimvtis.htm
and download the VTRIS User Guide.
